Amazon.com: 2GB Graphics Video Card Replacement for Apple iMac Mid-2011 27 Inch A1312 Core i7 3.4 MD063LL/A MD063 Desktop PC Computer, ATI Radeon HD 6970 GDDR5 2 GB, New GPU Upgrade Repair
MD063LLA Apple iMac 27" Core i7-2600 Quad-Core 3.4GHz All-In-One Computer - 4GB 1TB DVD±RW Radeon HD 6970M (Mid 2011) - B